Window balance



J. W. SCOTT WINDOW BALANCE INVENTOR.

Cet. 29, 1968 Filed Sept. 19, 1966 United States Patent ti 3,407,434 WINDOW BALANCE `lohn W. Scott, 1510 Johanna St., Houston, Tex. 77055 Filed Sept. 19, 1966, Ser. No. 580,429 7 Claims. (Cl. 16-193) ABSTRACT F THE DISCLOSURE A braking device for holding a window sash at a predetermined point along a generally U-shaped side jamb of a window frame which includes a housing which can be mounted along the top rail of a singleor double-hung window sash or the bottom rail of a single-hung sash. The housing contains a plurality of inter-linked braking elements operatively expansible and contractable in position to vary the frictional contact between the braking elements and the U-shaped side jambs of the window frames.

The present invention is directed to a balancing device for singleand double-hung windows. In a more specific aspect, the present invention is directed to a balancing device for singleand double-hung windows which may be conveniently mounted on the top rail of the lower 'sash of singleand double-hung windows and to the bottom rail of the upper sash of double-hung Windows.

In the prior art there are numerous 4balancing devices for singleand double-hung windows which rely upon springs, counterweights and the like. However, all of these devices are of complex construction and require considerable maintenance.

Accordingly, it is an object of the present invention to provide a balancing device which may be 'surface-mounted on the sashes of single. or double-hung windows with the channel formed by the frame jambs providing a braking surface for the device.

Another object of the present invention is to provide a window balancing device which ofers no obstruction to view and permits maximum opening of the window.

A still further object of the present invention is to provide a window balancing device which is relatively wear proof and is easily replaceable by the home owner in the unlikely event of failure.

Another and further object of the present invention is to provide a window balancing device which olfers the manufacturer the advantages of eliminating many costly operations, reduces his inventory requirements, eliminates balance failure in handling and shipping and eliminates costly eld maintenance and repairs.

Yet another object of the present invention is to pro-- vide a window balancing device, wherein a single unit may be mounted on either side or the top or `bottom of a sash frame.

These and other objects and advantages of the present invention will be obvious from the following detailed description when read in conjunction with the drawings, wherein:

FIGURE 1 is a front view of a balancing mechanism oriented for attachment to the left side of a window;

FIGURE 2 is a side view, partially in section, of the balancing device of FIGURE l; and

FIGURE 3 is a side view, partially in section, of the balancing device of FIGURE l in place in the side jarnb of a window.

Briey, in accordance with the present invention, a braking mechanism for holding a window sash at `a predetermined point along a generally U-shaped side jamb 3,467,434 Patented Oct. 29, 1968 of a window, comprises a housing adapted to be attached to a horizontal portion of a window sa'sh and having an aperture therethrough transverse to and situated between the legs of the jarnb and a braking means mounted within the aperture including a rst braking element in contact with one leg of the jarnb and a second braking element in contact with the other leg of the jarnb and a link operatively connecting the two braking elements to permit limited horizontal and vertical movement of one braking element relative to the other whereby the braking means frictionally contacts the legs of the U-shaped jamb, contracts and reduces frictional drag on the legs of the jarnb upon upward movement of the sash, and expands and increases the frictional drag on the legs of the jamb upon downward movement of the sash.

Referring specifically to the drawings, the numeral 10 generally designates a frame or housing means for the lbalancing mechanism. Housing 10 is made up of an upright section 12 and a horizontal extension 14. Formed transversely through upright section 12 of housing 10 is a rectangular opening or aperture 16 adapted to Ieceive the braking mechanism of the balancing device of the present invention. Housing 10 may :be formed either by extrusion or molding from any suitable material adequate to perform the functions thereof and withstand the stresses applied thereto. Mounted somewhat loosely within aperture 16 is a braking mechanism, including, a plurality of coacting elements. The braking mechanism includes a main braking shoe or guide shoe 18. Itis to be seen that main braking shoe 18 is slightly smaller in width than the width of aperture 16 and much smaller in height than aperture 16, so that it may slide up and down freely in aperture 16. Formed in the interior side of 'shoe 18 is central slot 20. Mounted within central slot 20 is link arm 22. Link arm 22 has formed, adjacent one end thereof, and centrally thereof a horizontal slot 24. Passing through horizontal slot 24 and thence the side flanges or walls 26 of slot 20 is pin 28. Pin 28 permits link 22 to rotate thereabout as limited only by the dimensions of slot 20 and also to move horizontally with relation to main brake shoe 18. Slidably mounted against main brake shoe 18 and sliding on walls 26 of brake 18 is secondary braking or slip shoe 30. Secondary braking shoe 30 has a central slot 32 formed in the face of its inner edge, which is of 'suliicient size to receive link 22. Link 22 is rotatably mounted in side flanges or walls 34 of secondary brake 30 `by means of a pin 36 passing through a round aperture 38 in link 22. Thus, it may be seen that secondary shoe 30 is operatively connected to primary shoe 18 in a manner such that it is able to slide a limited distance vertically with respect to shoe 18 while at the same time expanding the brake mechanism as it travels up main brake shoe 18 and contracting the brake mechanism as it travels downwardly with respect to main brake shoe 18. Thus, when brake 'shoe 30 is in its uppermost position with relation to brake shoe 18 a wedging action is provided in the window jarnb, as hereinafter pointed out. Mounted in a bore in the bottom, interior edge of secondary brake shoe 30 and in a bore 42 in the top, interior edge of extension 44 of main brake shoe 18 is a helical compression spring 46. It is to be seen that spring 46 normally urges 'secondary brake shoe 30 upwardly with respect to main brake shoe 18, and thus tends to eX- pand the braking mechanism. Also, as previously pointed out, the aperture 16 is greater in height than main brake shoe 18 and, therefore, the braking mechanism is also free to slide vertically within housing 10.

The attachment of the braking mechanism to a win- 3 dow is illustrated in FIGURE 3. As previously indicated, FIGURE l shows the mechanism of the present invention oriented in a fashion such that it would be attached to the left side of top rail of the bottom sash of a doublehung window. Thus, extension 14 of housing 10 would extend to the right. Extension 14 is provided with holes 48 for receiving self-tapping screws 50 for attachment of the mechanism to the top rail 52 of a window unit. The frame jamb of the window is shown generally as numeral 54 and has, due to its configuration, a track or channel S6 formed between anges SS. Therefore, main brake shoe 18 and secondary brake shoe 30 are in contact with flanges 58 of the channel of jamb 54. The lntel or top channel of the window frame is shown as element 60.

The operation of the balancing mechanism of the present invention will now be explained with reference to the drawings. As previously indicated, the balance is mounted on the top rail of the bottom sash of a doubleor single-hung window, or on the bottom rail of the top sash of a double-hung window. In this position a pair of such balancing mechanisms is mounted on each sash, one on the right and one on the left, as previously indicated, with the braking mechanism in contact with the side flanges 56 of the side jamb 54. As a lifting or raising force, equal to the weight of the sash, is applied the frame 10 contacts the bottom main braking shoe 18 compressing 'spring 46 slightly. This slight movement of shoe 18 and the compression of spring 46 moves shoe 18 a short distance upwardly with respect to shoe 30, decreasing the wedging action of braking shoes 18 and 30 thus decreasing the friction between the braking shoes and anges 58 of jamb 54. This, of course, allows the window sash 52 to move freely upwardly until the lifting or raising force is released. When the 'lifting or raising force on sash 52 is released, contact is made between the top of housing 10 and the top end of main lbrake shoe 18. This in turn moves main brake shoe 18 downwardly with respect to brake shoe 30 and causes a wedging action of brake shoes 18 and 30 against flanges 58 of side jamb channel S4. This Wedging action is of course assisted by compression spring 46. Thus friction between the braking mechanism and the window jamb is increased until it is sufficient to actually hold the window in the selected position. This wedging action will hold the window in position until the wedging force is released by an upward movement which releases the shoe, as previously explained, or by a downward or closing force 'sufficient to overcome the friction of the braking mechanism.

The braking mechanism, as previously indicated, is commensurately smaller than the tubular or interior dimension of aperture 16 of housing 10. ln actual practice the braking mechanism is 1i-inch smaller in height than opening 16 of the housing and about 1,2inch in width smaller than the cross-section of aperture 16. Thus, the braking mechanism may float freely within the housing, which is necessary to proper functioning of the device. The cross-section or horizontal dimensions of the braking mechanism may of course be varied to adapt the balancing mechanism to a wide variety of window sashes. Appendages may also be added to serve as sash guides to prevent racking of the sash during raising or lowering. In the event a stiffer lifting force on the secondary braking shoe is desired, the braking shoe compression spring may be made to increase the wedging action of the brake by utilizing a heavier spring. Preferably, the braking shoes 18 and 30 are made of molded nylon. Also preferably, the slips or slide portion of brake shoe 18 may be covered with a stainless steel shim 62 for purposes of improving the wear qualities of the balancing device. The link arm 22 may be made of nylon or stainless steel, pins 28 and 36 may be made of nylon or stainless steel and compression spring 46 may be made of stainless steel.

While a specitic embodiment of the present invention has been shown in detail for purposes of illustration and to show the best mode of manufacturing the present invention, it is to be understood that various modifications and variations of the present mechanism will occur to one skilled in the art without departing from the inventive concept involved herein. Accordingly, it is to be understood that the present invention is limited only in accordance with the appended claims.

I claim:

1. A device for holding a window sash at a predetermined point along a generally U-shaped side jamb of a window frame, comprising:

(a) a housing means adapted to be attached to a horizontal portion of said window sash between the legs of said U-shaped jamb and having an aperture therethrough transverse to said legs of said jamb; and

(b) a braking means mounted within said housing and adapted to frictionally contact said legs of said U- shaped jamb, to contract and reduce the frictional drag on said legs of said U-shaped jamb upon upward movement of said sash and to expand and increase the frictional drag on said legs of said U- shaped jamb upon downward movement of said sash, including, a iirst braking element, smaller in vertical dimension than said aperture, mounted for free vertical movement within said aperture in contact with one leg of said U-shaped jamb and a second braking element, smaller in vertical dimension than said rst braking element, mounted within said aperture in contact with the other leg of said U-shaped jamb and operatively connected to said first braking element to move horizontally and vertically with respect to said first braking element.

2. A device in accordance with claim 1 wherein the rst and second braking elements are a pair of wedge elements.

3. A device in accordance with claim 2 wherein one of the wedges has an upwardly and outwardly inclined surface and the other of the wedges has an upwardly and inwardly inclined surface in contact with said inclined surface of said one wedge.

4. A device in accordance with claim 2 wherein the rst and second braking elements are operatively connected by link means adapted to permit one of said wedges to move horizontally and vertically with respect to the other of said wedges.

5. A device in accordance with claim 2 wherein the aperture and the larger of the two wedges are designed to permit free vertical movement of said larger wedge and to stop said vertical movement after a predetermined movement in either vertical direction.

6. A device in accordance with claim 2 wherein cornpression spring means is mounted within the braking means and is adapted to normally urge said braking means to expand horizontally.

7. A device for holding a window sash at a predetermined point along a generally U-shaped side jamb of a window frame, comprising:

(a) a housing means adapted to be attached to a horizontal portion of said window sash between the legs of said U-shaped jamb and having an aperture therethrough transverse to said legs of said jamb; and

(b) a braking means mounted within said housing and adapted to frictionally contact said legs of said U-shaped jamb, to contract and reduce the frictional drag on said legs of said U-shaped jamb upon upward movement of said sash and to expand and increase the frictional drag on said legs of said U- shaped jamb upon downward movement of said sash, including, a first braking element mounted Within said aperture in contact with one leg of said U- shaped jamb, and a second braking element, smaller in vertical dimension than said first braking element, mounted within said aperture in contact with the other leg of said U-shaped jamb and operatively connected to said first braking element to move hori- 5 6 zontally and vertically with respect to said rst brak- 1,271,517 7/ 1918 ODonnell 49-421 ing element. 1,610,084 12/ 1926 Frowenfeld 49-451 XR References Cited UNITED STATES PATENTS 171,695 1/1876 Payson 49 151 XR 5 BOBBY R. GAY, Przmary Exammer. 275,903 4/ 1883 Gross 49-421 XR J. L. KOHNEN, Assistant Examiner.

2,439,046 4/ 1948 Grim 49-421 

